Validation of the full spectrum analysis technique for determining radionuclide activity in environmental samples using HPGe spectrometry

Tóm tắt

Introduction: Analytical method validation is crucial for ensuring data quality in environmental radioactivity monitoring. This study presents a systematic validation and comparative assessment of two prominent techniques for high-purity germanium (HPGe) gamma-ray spectrometry: full spectrum analysis (FSA) and the traditional energy window analysis (EWA).

Methods: FSA models a measured spectrum as a linear combination of basis spectra, while EWA relies on individual peak-area analysis. The accuracy and robustness of both methods were rigorously evaluated by analyzing a diverse set of IAEA reference materials with varying matrices and activity levels.

Results: Both methods demonstrated high accuracy, with most results for both FSA (71%) and the corrected EWA (86%) falling within a ±15% relative deviation from the certified values. EWA showed exceptional accuracy for nuclides with clear, high-intensity peaks. FSA provided comparable or slightly better results for certain complex spectra and low-activity nuclides. Additionally, a strong physical correlation (R² = 0.89) between the FSA background-scaling factor and sample density was confirmed, highlighting FSA’s capability to partially compensate for matrix effects.

Conclusion: This validation study confirms that both the corrected EWA and FSA are highly accurate, precise, and reliable methods for environmental radioactivity analysis. EWA exhibited slightly more consistent accuracy across this dataset; however, FSA can serve as a powerful complementary tool, excelling in cases with complex interferences. The choice of method is application-dependent, but both are suitable for routine use in accredited laboratories.